This invention is concerned with nonionic surface-active agents prepared from mixtures of alcohols containing from 8 to 20 carbon atoms by the sequential addition of ethylene oxide, propylene oxide and ethylene oxide. Such surfactants have lower pour points than straight ethylene oxide adducts having corresponding cloud points. Surface properties are not appreciably affected.
It has long been the practice to prepare surface-active agents by the addition of ethylene oxide to long chain alcohols. It is also well known to prepare mixed adducts of ethylene oxide and propylene oxide. Adducts containing a random distribution of oxyethylene and oxypropylene groups and adducts containing discreet blocks of polyoxyethylene and polyoxypropylene chains have been prepared. The straight ethylene oxide adducts often contain solids, making them difficult to handle at temperatures ordinarily encountered. The use of premixed ethylene oxide and propylene oxide results in a surfactant product having a lower pour point; but the product is not entirely satisfactory in that it may contain solids; may not be satisfactorily biodegradable, etc.